As the above instrumental device, for example, as shown in FIG. 9, a meter 101 mounted on a vehicle or the like as a mobile object is known (for example, see PTL 1). The conventional meter 101 shown in FIG. 9 includes: a dial plate (not shown) formed in a circular plate shape, and on which indexes (not shown) indicating a condition of the mobile object are arranged in a circumferential direction thereof; and a case 103 provided with a concave 131 formed in a concave groove shape along the indexes, and to which the dial plate is attached so as to cover an opening of the concave 131; and a light source 104 provided on a rear side of the dial plate in the concave 131 opposite to the index, and emitting light toward the index. Further, FIG. 9 shows the conventional meter 101 of which dial plate (not shown) is removed. A chain line in FIG. 9 shows a range L to which the light from the light source 104 is applied.
The case 103 is provided with a light shield 132 formed in a circular shape in a plan view and interposed between the index and the light source 104.